This invention relates to oxyalkylated products. More particularly, this invention provides a process for preparing polyol products, and the use thereof in preparing polyurethane compositions.
Polyol products are of interest for making a variety of polymeric products such as polyester and polyurethanes. Polyurethanes have gained widespread acceptance in industry for a variety of uses. Cellular polyurethanes, in particular, are used for a wide variety of purposes, for example, as packaging materials, cushioning and as insulation in the construction industries. Depending uon the uses intended for the products the specifications and costs can vary widely. Some uses of polyurethanes require rigid foams; other uses require semi-rigid or flexible foams. Also, the use of polymeric materials in some cases requires that they have built in flame retardant properties, other uses of polyurethanes do not require extensive burn resistant properties. It would be desirable from both economic and technological viewpoints to have a single process which could be adapted to produce polyol products which meet a variety of product specification and cost requirements, while minimizing undesired side reactions which have occurred. Polyols, including polyoxyalkylation reaction products, are used as an active hydrogen-containing component in polyurethane manufacturing formulations. When flame retardant properties are required in polyurethane foams, it is known to use halogenated compounds and/or derivatives of phosphorus acids as active hydrogen compounds in the polyurethane formulation. Sometimes boron and antimony compounds have been used as additives to the formulation in order to enhance the flame retarding properties of the resulting polyurethane.
While all of the foregoing substances are effective in imparting some degree of flame-resistance to polyurethane plastics, the disadvantage associated with all of these approaches is that the use of increasing quantities of such substances impairs the mechanical and physical properties of the polyurethane product. Also, as the quantity of flame resistance-imparting agents is increased, the problem of blending such agents into the polyurethane formulation is increased.
To be acceptable in the building and construction industry, polyurethane foam spray systems must have a sufficiently low viscosity and must possess a shelf-life of at least six months. The preparation of such polyurethane foam systems is exemplfieid in U.S. Pat. No. 3,091,551. The flame-resistance of polyurethane foams is evaluated by standard tests, such as the ASTM E-84 Tunnel Test, the Butler Chimney Test and the ASTM D-1692-68 Flame Test. Several methods have been considered by those skilled in the art in an attempt to provide polyurethane foam systems having the above-enumerated properties. Various halogen and/or phosphorus-containing compounds have been employed either as the polyol component of the system or as an additive thereto. See, for example, U.S. Pat. No. 3,364,153.
The usual way for making oxyalkylated polyols for use in making polyurethane foams and polymers has been to use an alkaline catalyst in the polyhydric alcohol/alkylene oxide reaction mixture. However, the resulting polyol reaction mixtures generally contain at least about 0.1 to about 0.5 percent by weight of the alkaline catalyst. Presently steps are taken to remove as much of that alkaline catalyst as possible, preferably down to at least about 5 parts per million because it is known that such alkaline materials in the mixtures interfere with the reaction between the oxyalkylated polyol product and the polyisocyanate in making polyurethanes. Undesired reactions such as gelation of the mixtures occur because of the presence of the alkaline material. It is desirable to provide the polyol and polyurethane making art with an improved, simplified process for making oxyalkylated products which can be used as the polyol reactant in polyurethane manufacture without having to remove substances which limit the utilities of the product or to be concerned with the undesired side reactions caused by alkaline catalyst residues which were carried through with the polyol.
Moore U.S. Pat. No. 2,253,723 discloses the addition of an epoxide to a polyhydric alcohol in the presence of a stannic chloride catalyst. This patent also suggests that similar reactions can be carried out with phenols. Marple U.S. Pat. Nos. 2,327,053 and 2,428,235 disclose the mono-addition of an epoxide to the hydroxy group of an alcohol or phenol in the presence of a metal halide catalyst, and suggests that the formation of secondary or higher products may be favored by decreasing the ratio of the hydroxy compound to the epoxide. MacMullen U.S. Pat. No. 2,401,261 discloses the preparation of solid 2-(pentachlorophenoxy)ethanol from pentachlorophenol and ethylene oxide in Example 1 thereof. Wismer U.S. Pat. No. 3,043,881 discloses the reaction of an epoxyalkyl pentachlorophenyl ether with an aliphatic alcohol in the presence of a Friedel-Crafts catalyst to obtain a mono-ether across the epoxide bond through one hydroxyl group of the aliphatic alcohol. None of the patents disclose the oxyalkylation of mixtures of phenols and non-phenolic active hydrogen compounds, and none of them disclose the use of the catalyst complex system disclosed hereinbelow.
The Austin/Pizzini/Levis U.S. Pat. No. 3,639,541 discloses an ester-containing polyol may be reacting (a) a polyhydroxyl-containing compound, (b) an acid or oxide of phosphorus (c) a halogen-containing organic acid anhydride and (d) an alkylene oxide. In some examples thereof the use of tri-n-butylamine as a catalyst is disclosed. However, the process of that patent and its resulting product is limited in the amount of oxyalkylation that occurs in those mixtures. The amine catalyst permits only 1 molecular equivalent of alkylene oxide to react per available reactive hydrogen, and to that extent that process is somewhat limited in the types of oxyalkylation products that it can produce.
The Pizzini/Levis U.S. Pat. No. 3,639,542 discloses an ester-containing polyol prepared by reacting (a) a neutral phosphate polyol, (b) a halogen-containing organic acid anhydride and (c) propylene oxide. The process of that thereof is limited in the amount of oxyalkylation that takes place in that mixture.
There continues to be a need for more efficient processes, and new economically-obtainable, flame-resistant oxyalkylated products which can be used for a variety of industrial applications, for example, for further reactions with polyisocyanates to make stable pour-in-place, slab stock and sprayable polyurethane foam formulations, for use in making flexible, semi-rigid and rigid foam materials which have applications in the insulation, building and packaging industries.
It is an object of this invention to provide a new, economical process for preparing oxyalkylation polyol products which do not require the use of basic catalysts.
It is a further object of this invention to provide an improved, adaptable process which can be used to prepare oxyalkylation polyol products of a broader range of desired molecular weight and hydroxyl number properties, depending upon the specifications and requirements called for by the use intended for such product.
It is a further object of this invention to provide a process for making an oxyalkylated polyol product which permits more than one mole of alkylene oxide addition per available hydrogen atom in the starting material.
It is a further object of this invention to provide an oxyalkylation polyol producing process in which polyoxyalkylation can be allowed to proceed to the desired degree of physical properties and in which the oxyalkylation reaction can then be controlled by terminating the oxyalkylation when the desired degree of oxyalkylation has taken place.
It is a further object of this invention to provide a simplified process for making phosphorus and halogen-containing oxyalkylated products, which are useful in combination with polyisocyanates for making flame-retardant polyurethane foams.
It is a further object of this invention to provide an improved oxyalkylation process for oxyalkylating mixtures of phenols, non-phenolic active hydrogen compounds and a phenol:aluminum or iron catalyst complex, to obtain substantially acid-free phosphorus and halogen oxyalkylated product mixtures, useful for making polyurethanes.